Organic composite material

ABSTRACT

A composite material comprising an organic crop cutting powder, starch, and a liquid, and a method of making molded products from the composite material. The manufactured products may be laminated or coated depending on their intended application.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the filing of U.S. ProvisionalPatent Application Serial No. 60/088,267, entitled Organic CompositeMaterial, filed on Jun. 5, 1998 and the specification thereof isincorporated herein by reference. This application is a 371 ofPCT/US99/12503 filed Jun. 4, 1999.

BACKGROUND OF THE INVENTION

1. Field of the Invention (Technical Field)

The present invention relates to a composite material derived fromagricultural products and agricultural by-products that can be formed ormolded into various shapes.

2. Background Art

Much effort has been expended in the effort to develop an inexpensivematerial that has a low or positive impact on the environment, and canbe used for forming various articles for industrial and consumer use. Todate, none of these efforts has been entirely satisfactory.

For example, U.S. Pat. No. 5,344,871, to Timm et al., teaches the use ofnaturally occurring binders derived from certain agricultural products,such as proteins from cereal grasses, leguminous plants, or from leaves.Grains that have had the starch removed in the process of formingalcohol or defatted corn germ may also be used to make an organicbinder. High temperatures and pressures are applied for a sufficienttime to alter or denature the molecular structure of the proteinresulting in polymerization. The shaping or molding process requires nochemical additives but it is useful to include sufficient amounts ofwater to increase heat transfer and to render the protein sufficientlyflexible to flow around the materials to be bound.

U.S. Pat. No. 4,306,059, to Yokobayashi et al., teaches the use of aspecific alphaglucan, termed Elsinan. Elsinan is a sugar comprised ofrepeating units of D-glucopyranose. An advantage of using Elsinan overother sugars, such as amylose, is that the formed products are moistureand water resistant, transparent, and storable for long periods of timewithout losing their desirable properties. Fillers can be mixed with theElsinan in the range of 10,000 to 0.0001, respectively, based on dryweight. A similar sugar, Pullalan, has been used in combination withwater soluble materials, such as starch, gelatin, or casein to bindchemical fertilizers in a form more suitable for application. U.S. Pat.No. 4,045,204, to Matsunaga et al.

SUMMARY OF THE INVENTION (DISCLOSURE OF THE INVENTION)

The present invention is of a composite mixture comprising an organicpowder, starch, and a liquid. In the preferred embodiment, the compositemixture comprises approximately one part organic powder of particle sizeless than or equal to approximately 1 mm, one part starch, and two partsliquid, preferably water. The composite mixture of may also comprisefibrous organic material when an increase in strength of the inventivematerial is desired. The organic powder may comprise any powdered cropcuttings, but preferably straw powder.

The invention is further of a method of making a formed product from theinventive composite mixture comprising the steps of: combining anorganic powder, starch and a liquid to form a slurry; pressing theslurry into a mold; heating the mold; and removing the formed productfrom the mold. In the preferred embodiment, the composite mixturecomprises approximately one part organic powder of particle size lessthan or equal to approximately 1 mm, one part starch, and two partsliquid, preferably water. The composite mixture may also comprisefibrous organic material when an, increase in strength of the inventivematerial is desired. Once all the above materials are combined to form aslurry, the slurry is pressed into a mold and heated to an appropriatetemperature, preferably at or above approximately 300° F. The organicpowder may comprise any powdered crop cuttings, but preferably strawpowder. After the removal of the molded product comprised of theinventive composite mixture, the molded product can.be optionally formedinto a laminated structure, coated or both finishing processes may beapplied. The formed product can be utilized as any disposable item forconsumer use, preferably a food container.

The present invention is also of a molded product comprising an organicpowder, starch, and a liquid. In the preferred embodiment, the particlesize of the organic powder is less than or equal to approximately 1 mm,and the composite mixture comprises approximately one part organicpowder, one part starch, and two parts liquid, preferably water.

A primary object of the present invention is to provide an inexpensive,biodegradable composite mixture that is easily shaped into variousformed products. After consumption, the resulting formed productsprovide a positive environmental benefit compared with materialspresently being utilized for similar industrial and consumer uses.

A primary advantage of the present invention is that it is comprised ofrelatively inexpensive and easily renewable materials.

An additional advantage of the present invention is the positive benefitit provides to the natural environment compared with other materialsused for similar purposes.

Another advantage of the present invention is its ability to be moldedinto a rigid form. The rigid form allows for a consistent andpredictable shape. Further, the strength of the resulting formedproducts can be adjusted to support a given load by varying thecomposition of the inventive composite mixture.

Still another advantage of the present invention is its heat insulationproperties, its electrical insulation properties, its acousticaldampening properties, as well as its ability to hold a rigid form for anextended period.

Other objects, advantages and novel features, and further scope ofapplicability of the present invention will be set forth in part in thedetailed description to follow, taken in conjunction with theaccompanying drawings, and in part will become apparent to those skilledin the art upon examination of the following, or may be learned bypractice of the invention. The objects and advantages of the inventionmay be realized and attained by means of the instrumentalities andcombinations particularly pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated into and form a partof the specification, illustrate several embodiments of the presentinvention and, together with the description, serve to explain theprinciples of the invention. The drawings are only for the purpose ofillustrating a preferred embodiment of the invention and are not to beconstrued as limiting the invention. In the drawings:

FIG. 1 represents a cross-sectional view of a material of the inventioncomprising a mixture of fine powder and particles of sizes ofapproximately 1 mm of average size;

FIG. 2 represents a cross-sectional view of a material of the inventioncomprising a mixture of fine powder and particles of sizes not exceedingapproximately 6 to 7 mm in length;

FIG. 3 represents a cross-sectional view of a material of the inventioncomprising a mixture of fine powder and particles of variable size andlength;

FIG. 4 represents a cross-sectional view of a material of the inventionin laminate form with the two exterior surfaces of materials of theinvention made from fine powders, and an interior material of theinvention made from large grain powders and added fibers;

FIG. 5 represents a cross-sectional view of a material of the inventionin laminate form with one exterior surface made from a material such asoak veneer, and a plurality of either inventive or non-inventivematerials; and

FIG. 6 represents a cross-sectional view of a material of the inventionin laminate form with one exterior surface comprising wax paper, and twolayers of materials of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS (BEST MODES FOR CARRYING OUTTHE INVENTION)

The present invention provides a biodegradable composite mixture and amethod to make formed products of any shape from the composite mixture.The biodegradable materials of the invention include, but are notlimited to, agricultural products or by-products. The inventivecomposite material can be formed into disposable cups, plates,flowerpots, or acoustical or building panels. After use, the materialcan be discarded with little or no negative environmental impact.Because the material comprises organic constituents, the materialdegrades with relative ease. For example, after industrial or consumerconsumption the inventive material can be used as mulch in gardens orflowerbeds, or placed in a typical backyard compost pile, thus providinga positive environmental benefit. The material may be utilized forpermanent solutions or for temporary solutions in industrial, consumerand post-consumer uses.

The material of the present invention comprises a mixture of starch, anorganic material in powder form, and a liquid. The organic powder mayalso be combined with varying combinations and sizes of fiber ornon-powder organic elements to meet specific design criteria for theparticular application of the material. The liquid preferably compriseswater, but may include alcohols, or mixtures thereof. The addition ofother organic compounds, such as formaldehyde, may be also be added tothe liquid where appropriate. The appropriate organic mixture, with orwithout added fibers, is combined with the liquid pressed into a mold,and formed into a rigid material by the application of elevated heat.The resulting product can be further modified by application of anexterior coating, such as wax or foil.

The present invention preferably combines starch, powdered straw, andwater as the liquid. Other organic materials in powdered orsemi-powdered form, including, such as crop cuttings or grass cuttings,may be substituted for the powdered straw. A preferred composition ofthe material is one part organic powder, e.g., straw powder, one partstarch, and two parts water. Fibrous or other non-powder organicmaterials may also be added to the pre-formed composite mixture toprovide additional strength to the final formed products. The strengthof the resulting formed product is also dependent on the grain size ofthe organic powder. In general, the larger the grain sizes of thepowder, the stronger the finished product. Utilization of a relativelyfine powder in combination with the starch and water results in afinished product with a consistent appearance and a glossy sheen. Thefinal formed product can also be manufactured as a laminate, as shown inFIG. 4.

Because the present invention results in a rigid material, the materialof the invention can be used as a substitute or replacement for manyother rigid materials, such as disposable cups and plates, acoustical orbuilding panels, as well as storage, packing, and food containers.Because the final formed products derived from the inventive materialsare rigid, the products can be shredded and applied as a mulch followingconsumption. The inventive material is subject to the samebiodegradation process as any other organic material, and thus blendswith the soil environment and adds nutrients to the soil followingdecomposition. At the consumer level, the consumed products derived fromthe inventive materials can be used as a compost material or mulch orother similar use. At the industrial level, the consumed products may bereclaimed or used as a composting agent.

INDUSTRIAL APPLICABILITY

The invention is further illustrated by the following non-limitingexamples.

EXAMPLE 1

The material of the invention will vary in shape and thickness dependingupon the desired and intended use. The material has been formed intovarious shapes and thickness, ranging from less than ⅛ inch to over ¼inch. In one example, the inventive material was formed into a plateapproximately ⅛ inch in thickness. When held to a heat source of over160° F. the formed product was shown to have an insulation value ofapproximately 95% of a comparable styrofoam™ product of equal thickness.In a stable and protected environment, (e.g., a dry indoor storageenvironment), the material has shown to be stable, not losing shape,color, or other physical characteristics over a period of 30 months.

EXAMPLE 2

The material of the invention has better sound dampening properties thanthat of the wood cedar. For comparison, a 90 decibel sound source wasapplied to both a one-quarter inch plate of cedar and a formed plate ofthe inventive composite material of similar thickness, the reflectedsound measured was 84 and 78 decibels, respectively. The electricalresistance of the formed inventive material is similar to that of wood.

EXAMPLE 3

The present invention includes laminate materials comprising a materialof the invention as a composite layer or layers. FIG. 4 represents alaminate comprising two exterior surfaces of material 10 made from finepowders, and an interior of material 12 made from larger grain powderand added fibers. The laminate can be formed by pressing the individualmaterials under appropriate temperatures and pressures, attaching thematerials with an adhesive, or by any combination of methods known inthe art.

EXAMPLE 4

The present invention includes laminate materials comprising at leastone of the materials of the invention as a composite layer. FIG. 5represents a laminate for home paneling comprising an exterior surfaceof oak veneer 14, and materials of the invention 16 and 18 or othermaterial 20. The interior material 20 can be a material such as a woodor synthetic ply, a fiber netting or cloth. The laminate can be formedby pressing the individual materials under appropriate temperatures andpressures, attaching the materials with an adhesive, or by anycombination of methods known in the art.

EXAMPLE 5

The present invention includes laminate materials comprising at leastone of the materials of the invention as a composite layer. FIG. 6represents a laminate for consumer use such as a food container with asurface of wax paper 30, and materials of the invention 32. The laminatecan be formed by pressing the individual materials under appropriatetemperatures and pressures, placing the wax paper in the mold prior toinjection of the present invention material (in slurry form), or by anycombination of methods known in the art.

The preceding examples can be repeated with similar success bysubstituting the generically or specifically described reactants and/oroperating conditions of this invention for those used in the precedingexamples.

Although the invention has been described in detail with particularreference to these preferred embodiments, other embodiments can achievethe same results. Variations and modifications of the present inventionwill be obvious to those skilled in the art and it is intended to coverin the appended claims all such modifications and equivalents. Theentire disclosures of all references, applications, patents, andpublications cited above are hereby incorporated by reference.

What is claimed is:
 1. A composite mixture consisting essentially ofpowdered crop cuttings, starch and a liquid.
 2. The composite mixture ofclaim 1 wherein the powdered crop cuttings are straw powder.
 3. Thecomposite mixture of claim 1 consisting essentially of approximately 1part crop cuttings, one part starch, and two parts liquid.
 4. Thecomposite mixture of claim 1 wherein the liquid is water.
 5. Thecomposite mixture of claim 1 wherein the particle size of said powderedcrop cuttings is predominately less than approximately 1 mm.
 6. A methodof making a formed product, the method comprising the steps of: a)forming a slurry consisting essentially of powdered crop cuttings,starch and a liquid; b) pressing or injecting said slurry into a mold;c) heating the mold; and d) removing the formed product from the mold.7. The method according to claim 6 wherein the step of heating the moldcomprising heating the mold to at or above approximately 300 degrees F.8. The formed product made by the method of claim
 7. 9. The method ofclaim 6 wherein the powdered crop cuttings are straw powder.
 10. Theformed product made by the method of claim
 9. 11. The method of claim 6consisting essentially of approximately 1 part crop cuttings, one partstarch, and two parts liquid.
 12. The formed product made by the methodof claim
 11. 13. The method of claim 6 wherein the liquid is water. 14.The formed product made by the method of claim
 12. 15. The method ofclaim 6 wherein the particle size of said powdered crop cuttings ispredominately less than approximately 1 mm.
 16. The formed product madeby the method of claim
 15. 17. A formed product made by the method ofclaim
 6. 18. The formed product according to claim 17 having acharacteristic selected from the group consisting of a insulation valueapproximately equal to that of insulating foam of equal thickness,acoustical sound dampening properties similar to those of cedar wood ofequal thickness, being an electrical insulator, and combinationsthereof.